The pillar to the rear of the forward door of a vehicle is called a B-pillar. The pillar is substantially intended to provide protection in lateral collisions, and controlled deformation of it in a lateral collision is desired for best possible passenger protection. EP-1 180 470 A1 refers to a B-pillar which has a soft lower portion and promotes a controlled mode of deformation. U.S. Pat. No. 6,820,924 refers to a B-pillar which has two very narrow soft band as deformation triggers at a distance from the lower fastening portion of the pillar.
The object of the invention is to further improve a B-pillar, and in accordance with the invention the less strong portion has a height of at least 30 mm, extends less than ⅓ of total height of the pillar, and is so positioned that the lower fastening portion is predominantly martensitic. The invention is defined by the claims.